Clinical Characteristics and Outcomes in Adults with Anti-IFN-γ Autoantibody-Associated Immunodeficiency and Skeletal Involvement: A 10-Year Retrospective Cohort Study

Purpose Anti-interferon-γ autoantibodies (AIGAs)-associated immunodeficiency is a rare, adult-onset disorder characterized by multi-system infections with geographic variability. However, the clinical features and prognosis related to skeletal involvement remain unclear. Methods A 10-year retrospective study of AIGAs-positive skeletal involvement with HIV-negative patients from Guangxi, China. Results A total of 103 patients (median onset age: 55 years; median follow-up: 28.40 months), hypertension (29.13%) and HBV carriage (10.68%) were prevalent underlying diseases. Cough/sputum (66.99%) was the predominant initial symptom, while bone pain (21.36%) was less common. Among those with bone involvement, peripheral lymphadenopathy (86.41%) and cough/sputum (85.44%) were highly prevalent, unlike bone/joint pain (37.86%) and myalgia (14.56%). Most patients exhibited elevated levels of white blood cells, neutrophils, C-reactive protein, procalcitonin, erythrocyte sedimentation rate, globulin, immunoglobulin (Ig) G, and IgE. The predominant types of infection were disseminated Talaromyces marneffei (TM) (63.11%) and non-tuberculous mycobacteria (NTM) (55.34%), with an increasing trend of co-infection observed. Chest CT revealed lung involvement in all patients, with 63.11% exhibiting bone lesions. Bone emission computed tomography (ECT) showed abnormal uptake in the thoracic (75.73%) and lumbar vertebrae (56.31%); 63.11% of patients had bone destruction, of which 13.59% were osteolytic. All patients received full-course anti-infective therapy, some received individualized immunotherapy, and 19.41% required surgical intervention. Conclusion Skeletal involvement in AIGAs syndrome is common yet occult, presenting as disseminated infection, with TM and NTM co-infection complicating the course. The axial skeleton is frequently involved, with early detection by skeletal ECT enabling comprehensive treatment and precise management to improve prognosis.